single phase brushless motor? - Page 2 - RC Groups
Shop our Airplanes Products Drone Products Sales
Thread Tools
Nov 18, 2002, 09:50 AM
Registered User
That looks great, i'm going to build one of these.

How do you keep the windings from touching the rotor, or are they completely solid after you have CA'd them together? If so how do you get the kitchen wrap out after building the windings?

I'm interested to know how your sensorless controller senses, since I can't see when the coil would not be energised during a single rotation, and being single phase you do not have a spare phase for feedback.

Where did you see that magnet? i'd like order some of them.

This is very exciting for a lightweight ultra high kv edf motor. And the controller is very simple and cheap.

btw, do any of you guys know how to build a switched reluctance motor. It is supposed to be fairly simple, but i've found no diy pages on the subject.


Sign up now
to remove ads between posts
Nov 18, 2002, 04:10 PM
homo ludens modellisticus
Ron van Sommeren's Avatar
Originally posted by stumax
... I found a source of 12mm dia x 32 mm long with 5mm hole, polarised across the diameter, quite inexpensive, but not high temp grade NdFeB ...
Hi Stu, where do you get your magnets from?

Met vriendelijke groet Ron van Sommeren
homebuilt e-motor discussion group.
Last edited by Ron van Sommeren; Nov 18, 2002 at 04:16 PM.
Nov 18, 2002, 04:43 PM
The blade numbers go up to 11
stumax's Avatar
Joe and Ron, I found a company called Dexter Magnetic Technologies . The part number is PN36A1284B, you'll find it if you click on "permanent magnets" then "neodymium iron boron" the scroll down until you find "rings". The part is listed there. Joe, as far as switched reluctance motors go you'll be on your own. I intend to make one as I believe the they will replace our permanent magnet motors one day. They offer significant benefits in terms of power density due to the rotor being made with teeth rather than solid (even though iron is more dense then NdFeB) but the most significant thing for all of us tinkerers is that there are no magnets to buy and fry when things get too hot. The down side is the horrible noise they make and the vibration (allegedly). You won't be able to use a brushless controller so there's another project in it's own right. They are gaining poularity in industry so it wont be long until there are driver chips available, but I think most of them will be for 5 or six poles. When I do my 2 pole single phase brushless I shall be trying a two pole switched reluctance rotor as well, I'll keep you posted if you like. cheers, Stu.
Nov 19, 2002, 08:12 AM
Registered User
I'd be really interested in how your switched reluctance motor turns out, I think you could use the same sensored controller you build for the single phase brushless.

I've thought about using the armature minus its windings (with a suitable number of poles) from a brushed dc motor for the rotor. However I think you also need to have iron in the windings to get any efficiency out of the design.

I really like the simplicity of the slotless design being described here. Just wish there was an 'idiots guide' to putting one together.

Nov 19, 2002, 09:02 PM
Senior Member
zagisrule!'s Avatar
Wow takao!

Thanks alot for the schematics, it was exactly what I needed. I will be trying this soon. You are obviously very smart, jeez, that is incredible for someone only working on thier hobby. I can't imagine what you design at your job!

Again Thanks!
Dec 30, 2002, 12:03 PM
Registered User


I tested this system.
Efficiency ups about 30%.
The problem is Cx=1000uF($600). I need inexpensive small ceramic high cap.
Jan 02, 2003, 08:45 PM
Registered User

Simplest motor

You need very low internal resistance battery to drive this.
Because ...
Jan 02, 2003, 08:46 PM
Registered User

system works under 50% duty

You must apply the power in short period into the single phase motor.
Jan 03, 2003, 06:21 AM
Registered User

Brushless/Sensorless/Coreless driver

You need the crank up for starting.
Last edited by Takao Shimizu; Jan 03, 2003 at 06:24 AM.
Jan 03, 2003, 06:35 AM
Registered User

Brushless/Sensorless/Coreless driver

Here is the source code.
Mar 11, 2005, 05:38 PM
Registered User
Any new developments on these single phase brushless motors? Last post was over 2 years ago....
Oct 10, 2006, 08:30 AM
Registered User
Takao Shimizu wich web address for you

why dont post simple cdrom motor speed controller without micro controller
market meny ic availabe why dont try

Thread Tools